The present invention relates generally to a machine and method for knurling cylindrical workpieces and specifically to a machine that knurles an end portion of a hypodermic or biopsy needle located adjacent to its tip. This knurling allows the tip of the needle to be more easily seen by medical imaging apparatus.
Often during a medical procedure, medical personnel utilize a laser or ultrasound apparatus for instantaneously viewing a particular organ or cavity within a patient. It is often necessary to remove a sample of tissue or fluid from the respective internal organ or cavity. To remove the required sample matter, a needle such as a hypodermic needle or a biopsy needle is inserted through the patient's skin and into the area where the sample matter is to be removed. When the end or tip of the needle is within the desired region, the sample matter is withdrawn through the needle and into the capturing apparatus, typically a syringe.
It is highly advantageous for the medical personnel to be able to view the needle, especially the needle tip, and know its exact location as it is inserted into the body cavity. In this way, when the needle tip enters the desired or targeted cavity or organ, the doctor knows that he or she is removing the desired matter from the patient because the location of the sampling end or needle tip may be seen in relation to the targeted area of the organ or cavity from which the sample is to be withdrawn. Without some type of visual aid, the doctor or medical technician must otherwise guess or estimate when the needle tip is correctly positioned within the cavity or organ and when is the proper time to withdraw the required fluid or tissue.
The smooth tip and body of a hypodermic or a biopsy needle does not produce a visible image on a laser or ultrasound monitor. Because the tip and body directly reflect the ultrasonic waves emitted by the machine in the same way, no differential is produced and the needle does not appear in the resulting image displayed on the monitor. By cutting or forming a knurl or pattern near the end or tip of a needle, the ultrasonic waves are not directly reflected in the same manner at the tip as at the body; a differential is produced. The knurled portion of the needle now becomes visible on the resulting image displayed on the screen or monitor. By knowing exactly where the knurled portion of the needle body is, the doctor can easily determine where the tip of the needle is with respect to the selected body cavity or organ which also appears on the monitor. Thus the doctor can be assured that he or she is withdrawing the desired matter from the patient and not matter from another organ, tumor, or body cavity. The guess work as to when the needle tip is properly located within the selected area of the patient's body is eliminated.
It is an object of the present invention to provide a machine and method for forming or cutting a knurl near the end of a cylindrical workpiece or hypodermic or biopsy needle. It is a further object to provide a machine that is of a simple construction and design. It is yet a further object to form or cut the knurl without supporting the cylindrical workpiece or needle on its ends during the knurling process. It is yet a further object to provide such a machine that correctly positions the workpiece within the machine, forms the knurl at the predetermined location, and automatically ejects the workpiece when the knurling process is complete. Further, it is an object of the present invention to produce a knurled workpiece or needle by the process and machine disclosed herein. These and other objects of the present invention will become evident in the following descriptions
The inventor knows of no prior art that teaches or discloses the present invention.